In Marseille, an undercover detective is following Alain Charnier (Fernando Rey), a wealthy French criminal who runs the largest heroin-smuggling syndicate in the world. The policeman is assassinated by Charnier's henchman, Pierre Nicoli (Marcel Bozzuffi). Charnier plans to smuggle $32 million worth of heroin into the United States by hiding it in the car of his unsuspecting friend, French television personality Henri Devereaux (Frédéric de Pasquale).

In New York City, detectives Jimmy "Popeye" Doyle (Gene Hackman) and Buddy "Cloudy" Russo (Roy Scheider) are conducting an undercoverstakeout in Bedford-Stuyvesant, Brooklyn. After seeing a drug transaction take place in a bar, Cloudy goes in to make an arrest, but the suspect makes a break for it, cutting Cloudy on the arm with a knife. After catching up with their suspect and severely beating him, the detectives interrogate the man, who reveals his drug connection.

Later, Popeye and Cloudy go out for drinks at the Copacabana, where Popeye notices Salvatore "Sal" Boca (Tony Lo Bianco) and his young wife Angie (Arlene Farber) entertaining mob members involved in narcotics. They decide to tail the couple, and soon learn that the Bocas, who run a modest newsstand luncheonette, have criminal records: Sal for armed robbery and murder, and Angie for shoplifting. The detectives suspect that the Bocas, who frequent several nightclubs and drive expensive cars, are involved in some kind of criminal operation. They soon establish a link between the Bocas and lawyer Joel Weinstock (Harold Gary), who is part of the narcotics underworld.

Soon after, Popeye learns from an informant that a major shipment of heroin will arrive in the New York area. The detectives convince their supervisor, Walt Simonson (Eddie Egan), to wiretap the Bocas' phones, and they use several ruses to obtain additional information. Popeye and Cloudy are joined in the investigation by a federal agent named Mulderig (Bill Hickman). Popeye and Mulderig dislike each other based on having worked together in the past, with Mulderig holding Popeye responsible for the death of a policeman.

After Devereaux's Lincoln Continental Mark III arrives in New York City, Weinstock's chemist (Pat McDermott) tests a sample of the heroin and declares it the purest he has ever seen, establishing that the shipment could make as much as $32 million on a half-million dollar investment. Boca is impatient to make the purchase—reflecting Charnier's desire to return to France as soon as possible—while Weinstock, with more experience in smuggling, urges patience, knowing Boca's phone is tapped and that they are being investigated.

Charnier soon realizes he has been observed since his arrival in New York. He "makes" Popeye and escapes, waving tauntingly on the subway shuttle from Grand Central Station. To avoid being tailed, he has Sal Boca instead meet him in Washington DC, where Boca asks for a delay to avoid the police. Charnier, however, wants to conclude the deal quickly so he can return to France. On the flight back to New York, Nicoli offers to kill Popeye, but Charnier objects, knowing that Popeye would be replaced by another policeman. Nicoli insists, however, saying they will be back in France before a replacement is assigned.

Soon after, Nicoli attempts to shoot Popeye from the roof of Doyle's apartment complex but misses. Popeye chases after the fleeing sniper, who boards an elevated train at the Bay 50th Street Station in Bensonhurst. Doyle commandeers a car and gives chase along Stillwell Avenue. On the train, Nicoli hijacks the train, holds the driver at gunpoint, and kills a policeman who tries to intervene. When the motorman passes out, the train reaches the end of the line and slams into another train, hurling the assassin against the glass window. Popeye arrives and sees the killer descending from the platform. When he sees Popeye, he turns to run but is shot dead by Doyle.

After a lengthy stakeout, Popeye impounds Devereaux's Lincoln. In a police garage, he and his team take it apart piece by piece, searching for the drugs, but seemingly come up empty-handed. Then Cloudy notes that the vehicle's shipping weight is 120 pounds over its listed manufacturer's weight; they realize the contraband must still be in the car. This time they remove the rocker panels and discover the bags of heroin concealed in the body of the vehicle. The police then restore the car to its original condition and return it to Devereaux, who delivers the Lincoln to Charnier.

Charnier drives to an old factory on Wards Island to meet Weinstock and deliver the drugs. After Charnier has the rocker panels removed, Weinstock's chemist tests one of the bags and confirms its quality. Charnier removes the bags of drugs, and hides the money; concealing it beneath the rocker panels of another car that was purchased at an auction of junk cars, which he will then take back to France. With their transaction complete, Charnier and Sal drive off in the Lincoln, but almost immediately hit a roadblock with a large contingent of police led by Popeye, who playfully waves to Charnier. The police chase the Lincoln back to the factory, where Sal is killed during a shootout with the police and most of the other criminals surrender.

Charnier, however, escapes into the old warehouse and Popeye follows after him, with Cloudy joining in the hunt. When Popeye sees a shadowy figure in the distance, he empties his revolver a split-second after shouting a warning. The man whom Popeye kills, however, is not Charnier but Mulderig. Undaunted, Popeye tells Cloudy that he will get Charnier. After reloading his gun, Popeye runs into another room, and a few seconds later, a single gunshot is heard.[Note 2]

In an audio commentary track recorded by Friedkin for the Collector's Edition DVD release of the film, Friedkin notes that the film's documentary-like realism was the direct result of the influence of having seen Z, a French film. The film was among the earliest to show the World Trade Center: the completed North Tower and the partially completed South Tower are seen in the background of the scenes at the shipyard following Devereaux's arrival in New York.

Friedkin credits his decision to direct the movie to a discussion with film director Howard Hawks, whose daughter was living with Friedkin at the time. Friedkin asked Hawks what he thought of his movies, to which Hawks bluntly replied that they were "lousy." Instead Hawks recommended that he "Make a good chase. Make one better than anyone's done."[3]

Though the cast ultimately proved to be one of the film's greatest strengths, Friedkin had problems with casting choices from the start. He was strongly opposed to the choice of Hackman for the lead, and actually first considered Paul Newman (out of the budget range), then Jackie Gleason, Peter Boyle and a New York columnist, Jimmy Breslin, who had never acted before.[Note 3] However, Gleason, at that time, was considered box-office poison by the studio after his film Gigot had flopped several years before, Boyle declined the role after disapproving of the violent theme of the film, and Breslin refused to get behind the wheel of a car, which was required of Popeye's character for an integral car chase scene. Steve McQueen was also considered, but he did not want to do another police film after Bullitt and, as with Newman, his fee would have exceeded the movie's budget. Tough guy Charles Bronson was also considered for the role. Friedkin almost settled for Rod Taylor (who had actively pursued the role, according to Hackman), another choice the studio approved, before he went with Hackman.

The eventually successful casting of Rey as the main French heroin smuggler, Alain Charnier (irreverently referred to throughout the film as "Frog One"), resulted from mistaken identity. Friedkin had asked his casting director to get a Spanish actor he had seen in Luis Buñuel's French film, Belle de Jour, who was actually Francisco Rabal, but Friedkin did not know his name, and Rey, who had played in several other films directed by Buñuel, was instead contacted. After Rabal was finally reached, they discovered he spoke neither French nor English and Rey was kept in the film.[Note 3] In a further irony, after screening the film's final cut, Rey's French was deemed unacceptable by the filmmakers. They decided to dub his French while preserving his English dialogue.

The plot centers on drug smuggling in the 1960s and early '70s, when most of the heroin illegally imported into the East Coast came to the United States through France (seeFrench Connection). In addition to the two main protagonists, several of the fictional characters depicted in the film also have real-life counterparts. The Alain Charnier character is based upon Jean Jehan who was arrested later in Paris for drug trafficking, though he was not extradited since France does not extradite its citizens.[4] Sal Boca is based on Pasquale "Patsy" Fuca, and his brother Anthony. Angie Boca is based on Patsy's wife Barbara, who later wrote a book with Robin Moore detailing her life with Patsy. The Fucas and their uncle were part of a heroin dealing crew that worked with some of the New York City crime families.[5] Henri Devereaux, who takes the fall for importing the Lincoln to New York City, is based on Jacques Angelvin, a television actor arrested and sentenced to three to six years in a federal penitentiary for his role, serving about four before returning to France and turning to real estate.[6] The Joel Weinstock character is, according to the director's commentary, a composite of several similar drug dealers.[7]

The film is often cited as containing one of the greatest car chase sequences in movie history.[8] The chase involves Popeye commandeering a civilian's car (a 1971 Pontiac LeMans) and then frantically chasing an elevated train, on which a hitman is trying to escape. The scene was filmed in Bensonhurst, Brooklyn roughly running under the BMT West End Line (currently the D train, then the B train) which runs on an elevated track above Stillwell Avenue, 86th Street and New Utrecht Avenue in Brooklyn, with the chase ending just north of the 62nd Street station. At that point, the train hits a train stop, but is going too fast to stop in time and collides with the train ahead of it, which has just left the station.[Note 4]

The most famous shot of the chase is made from a front bumper mount and shows a low-angle point of view shot of the streets racing by. Director of photography Owen Roizman, wrote in American Cinematographer magazine in 1972 that the camera was undercranked to 18 frames per second to enhance the sense of speed. Roizman's contention is borne out when you see a car at a red light whose muffler is pumping smoke at an accelerated rate. Other shots involved stunt drivers who were supposed to barely miss hitting the speeding car, but due to errors in timing accidental collisions occurred and were left in the final film.[9] Friedkin said that he used Santana's song "Black Magic Woman" during editing to help shape the chase sequence; though the song does not appear in the film, "it [the chase scene] did have a sort of pre-ordained rhythm to it that came from the music."[10]

The scene concludes with Doyle confronting Nicoli the hitman at the stairs leading to the subway and shooting him as he tries to run back up them. Many of the police officers acting as advisers for the film objected to the scene on the grounds that shooting a suspect in the back was simply murder, not self-defense, but director Friedkin stood by it, stating that he was "secure in my conviction that that's exactly what Eddie Egan (the model for Doyle) would have done and Eddie was on the set while all of this was being shot."[11][12]

According to Roger Greenspun, "the ads say that the time is just right for an out-and-out thriller like this, and I guess that you are supposed to think that a good old kind of movie has none too soon come around again. But The French Connection...is in fact a very good new kind of movie, and that in spite of its being composed of such ancient material as cops and crooks, with thrills and chases, and lots of shoot-'em-up."[16]

In 2014, Time Out polled several film critics, directors, actors and stunt actors to list their top action films.[17] 'The French Connection was listed at 40th place on this list.[18]

The film has a 98% rating on Rotten Tomatoes with the consensus saying, "Realistic, fast-paced, and uncommonly smart, The French Connection is bolstered by stellar performances by Gene Hackman and Roy Scheider, not to mention William Friedkin's thrilling production." [19]

The film has been issued in a number of home video formats. For a 2009 reissue on Blu-ray Disc, William Friedkin controversially altered the film's color timing to give it a "colder" look.[23] Cinematographer Owen Roizman, who was not consulted about the changes, dismissed the new transfer as "atrocious".[24] On March 18, 2012 a new Blu-ray transfer of the movie was released. This time the color-timing was supervised by both Friedkin and Roizman, and the desaturated and sometimes over-grainy look of the 2009 edition have been corrected.[25][26]

^Title cards before the closing credits note that Joel Weinstock was indicted but had his case dismissed for "lack of proper evidence"; Angie Boca received a suspended sentence for an unspecified misdemeanor; Lou Boca received a reduced sentence; Devereaux served four years in a federal penitentiary for conspiracy; and Charnier was never caught. Popeye and Cloudy were transferred out of the narcotics division and reassigned.

^ abFriedkin recounts his casting opinions in Making the Connection: The Untold Stories (2001). Extra feature on 2001 Five Star Collection edition of DVD release.

^R42 cars 4572 and 4573 were chosen for the film and had no B subwayrollsigns because they were normally assigned to the N subway train. Consequently, they operated during the movie with an N displayed. As of July 2009, these cars were withdrawn from service, but are preserved as part of the Transit Museum fleet.